With an estimated 2.9 million new cases (54% occurring in men, 46% in women) and 1.7 million deaths (56% in men, 44% in women) each year, cancer remains a major public health problem in Europe and the rest of the world. An important modality in any therapeutic cancer strategy is the irradiation of the tumor with high energy photons or particles, i.e. radiotherapy. Developments in radiotherapy treatments have brought solutions that allow a more precise delivery of a higher dose to the tumor with fewer side effects to healthy tissues. Among the new techniques, including tomotherapy and cyberknife, both making use of 6 MV photons, charged particle beams, i.e. hadrontherapy, play an increasingly important role, due to its intrinsic high ballistic precision. Hadrontherapy can allow a very high dose to the target volume, while keeping the dose to the surrounding healthy tissues limited.
The advancement of these treatments is thoroughly related to advances in dosimetry, to fully exploit their high tumor conformity. There are several reported cases of accidents in conventional radiotherapy treatments due to malfunctioning of the equipment, or due to staff mishandling, as can be seen on Robert Johnston's database of radiological incidents and related events, http://www.johnstonsarchive.net/nuclear/radevents/index.html.
Unfortunately no on-line in-vivo dosimetry system is systematically in use in the clinical routine nowadays.
Prior art approaches to on-line in-vivo dosimetry, e.g. making use of diodes, MOSFET's, diamond detectors, TLD's or scintillators, perform a dose measurement at the level of the skin while a measurement in-situ, e.g. at the level of the tumor, would be preferable. Furthermore, methods are known in the application field to enable an in-situ dose assessment using implanted or intra-cavities dosimeters. However, such methods imply a degree of invasiveness. For example, US2011/121188 discloses a system which comprises internally positioning single-use MOSFET dosimeters in a patient's body to evaluate the radiation dose delivered during a medical procedure or treatment session, while the related patent application US2004/236207 discloses positioning single-use adhesive dosimeter patches just onto the skin of a patient. Therefore, the dosage of energy that is planned for, often cannot be measured, determined or monitored very accurately, in the tumor itself.